Propulsion power plant



y 8, 1952 G. PIELSTICK PROPULSION POWER PLANT Filed Dec. 29, 1949 I\NVENTOR GUSTAV P)ELSTlCK HTTORNE XS Patented July 8, 1952 I PROPULSIONPOWER PLANT I Gustav lielstick, Saint-Germain-enr'Laye, France,

QFFICE a pnca iqnne ember 29, 19.1.9; seam. 135,563 InFrance December30,1948

H 3 C aims- (aria-2) This invention relates to powerplantaespecially forthe propulsionof-ships, and more particularly power-plantsoi 'the typecomprising an engine group, such as a multi crankshaftengine group;

at least one crankshaft of which has an electric generatorcoupled'theretoh V; V '1 Power-plants are known particularly adapted forthe propulsion of ships, comprising an engine group having aplurality ofparallel spaced crankshaftsprojecting from both ends thereof, all ofsaid crankshafts being releasably coupled at one end-ftl ereofwith aload, such as-a ship's propeller shait, through an interposed commonspeed-reducenand at least-one of said crankshafts being releasablycoupled'at the opposite end with a rotary; electric machine usableeither as a generator to supply-electric current, as when the ship isinharbour for cargo-handling and similar requirements, or asa motor, whensupplied with: electric power from an external-source in ordereithertoparticipate" in the power-plants load-driving function, or to start the,power plant from an idle condition. The expression rotary electricmachinetis used in the specif cation and claims to designate 'an'electric generator adapted when desired to function 'as a-motor'. v

It is a general object of the present invention to provide animprovement in a power-plant oi the type just described, whereby acomplete selfcontained and autonomous power-plant system is obtainedhaving great advantages of economy and versatility over analogoussystems of prior art.

According to this invention, the said external I source of electricpower for supplying the said rotary electric machine when used as amotor is constituted by a separate generating set adapted to be drivenat least in a major proportion by the heat content of the exhaust gasesfrom said engine group.

Thus, my present invention may be described as comprising a combustionengine group having at least one crankshaft releasably coupled at one ofits projecting ends with a speed-reducer driving a load, a rotaryelectric machine releasably coupled with said crankshaft at its oppositeprojecting end, a generating set comprising a heatengine unit and agenerating unit coupled thereto, heat-recovery means for driving saidheat-engine unit of the generating set from the heat content of theexhaust gases of said combustion engine, and electric connections fromsaid generating unit to electric machine for energizing it for use as amotor.

The heat-recovery means used preferably comprise according to theinvention a. waste-heat boiler usingrthewexhaust gases of the combustionengine as'its heating medlum and the heat-engine unit of the generatingset accordingly comprises a steamturbine. Ji

- 3 vAccordingijo anothenfeature ofthe invention,

said! waste-heat boiler is preferably equipped withauxiliaryafiring;means such as;an oil burner or thelike; Whereby'theturbine unit of. thegenerating set may be operated when themainpowerplant is idle, and thus used to; start said main power-plant inoperation throughthe medium or the, electric machine and wherebyalso, inthe normal operation oicthelpow er-plant, a supplement, of power may beobtainedfor driving the load through the use of said auxiliaryfuel-firing mean,s. 7- a It has een Iound t at wh re the engine gr u of.the manpower-plant;c mpris s supe ch ed four-cycle diesel engines, thewaste heat of the exhaust gases, allowance haying been made for theemciency ratioof the waste heat boiler and the losses Over theelectriccircuit, makes possible a 10% increase in the propulsivepower oithe power-plant. In other Words, recovery of such waste exhaust heat ina boilerand the use of a generating set according to the invention willreduce the fuel consumption of the power plant by 10%.

The invention further comprises the method 01' operating a power-plantof the type described including an engine group having at least onecrankshaft releasably coupled at one of its ends with a reducer drivinga load and at its other end with a rotary electric machine, said methodcomprising recovering asubstantial part of the waste heat content of theexhaust gases of said engine, converting said heat into electric power,and feeding said electric power back to said rotary electric machine toparticipate in the load-driving func-- tion of said engine group.

An exemplary embodiment of the invention will now be described withreference to the accompanying diagrammatic drawing which illustrates acomplete power-plant according to the invention.

As shown in the drawing, an engine group I preferably of themulti-crankshaft diesel type for instance in my co-pending application,Serial Number 135,561, has all of its crankshafts, only two of which areshown in the drawing, releasably coupled through individual clutch meanswith a common reducer gearing 3 the output of which drives a load shaftsuch as a ship's propeller shaft 2. The lower one of the crankshafts iscoupled at its opposite projecting end, through a clutch as shown, witha rotary electric machine 4, i. e. an electro-dynamic rotary apparatusadapted to be operated both as an electric generator and as a motordepending on requirements.

The exhaust gases from the engine group I are conveyed through a conduitto a waste-heat boiler 6 of any suitable type in which they serve togenerate steam which is used to operate the turbine unit 7 of agenerating set 1 -8 the generating unit 8 of which is thus caused tosupply electric power through the electric connections 9 to the electricmachine 4 coupled with the engine group I.

A fuel-burner In or the like is shown as provided for auxiliary heatingof the boiler 6 for the purposes described. Thus, the burner 10 may beused to fire the boiler when the main powerplant I is idle, sufficientlyto set the electric machine or motor 4 running and thus start the mainengine I. The boiler may be of any conventional type, and comprise forinstance a series of tubular heating means 12 connected to. an inletll.i'

It will be obvious to those familiar withthe art that the installationdescribed iscapable of rendering many and invaluable services,especially owing to its extreme flexibility and versatility in adjustingitself to various circumstances and requirements. i2

1. In a power-plant in combination, a combustion engine group with aplurality of parallel spaced crankshafts, a reducer, clutch meanscoupling all of said crankshafts at one end thereof to said reducer,said reducer being drivingly coupled to a load, at least one rotaryelectric machine coupled to at least-one of said cranksha'fts at theopposite end thereof, a waste-heat boiler interposed in the exhaust ofsaid engine group to generate steam from the waste heat content of saidexhaust gases, auxiliary fuelburning means for said boiler, a generatingset including a steam turbine and a generating unit coupled thereto,steam connections from said boiler to said turbine and electricalconnections 4 from the output of said generating unit to said 4 rotaryelectric machine to energize said machine acting as an electric motor.

2. In combination with a power-plant of the type described including acombustion engine group having at least one crankshaft releasablycoupled at one end toa reducer driving a load and a rotary electricmachine coupled to the other end of said crankshaft, said machine beingboiler feeding said turbine, and electric circuit connections from theoutput of said generating set to said rotary electric machine foroperating said latter. machine as a motor.

3. The power-plant combination of claim 2 wherein auxiliary fuel firingmeans are provided in said boiler, and are adapted to heat it and tooperate; theturbine even when no exhaust gases are delivered from theengine.

v; GUSTAV PIELSTICK.

Q REFERENCES CITED The following references are of record in the file.of this patent:

'- UNITED STATES PATENTS Nurnber- I Name I Date 830,011 Schroeder Sept.4, 1906 I 891,350 Ma'scord June 23, 1908 981,081 Hammond-"- Jan. 10,1911 1,006,477; Guy Oct. 24, 1911 1,701,365 Herr Feb. 5, 1929 1,737,791Geisen Dec. 3, 1929 1,926,849 Gray Sept. 12, 1933 1,978,837 -ForslingOct. 30, 1934 2,213,045 -Kuhns Aug. 25, 1940 2,215,646 Kuhns Sept. 24,1940 2,405,676 Strub Aug. 13, 1946 1 FOREIGN PATENTS Number Country Date97,266 Sweden Apr. 27, 1937 537,483

Great Britain June 24, 1941

